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Apple Pencils don’t draw straight on replaced iPad screens

arstechnica.com

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Re: Apple Pencils don’t draw straight on replaced iPad screens

#11

Post by can16358p »

sbalamurugan wrote: post #8
spdustin wrote: post #4

Seems to me like it might be a calibration issue, and third parties aren’t able to perform the calibration.

Apparently it is not. The reddit thread has an ex Apple employee who runs repair shops in Germany. He says if you just change the serial number of a iPad screen(using specialised hardware) in existing iPad this issue will appear. This seems to indicate that it’s intentionally done by Apple. Other option is that Apple bakes in calibration details of all possible serial numbers in every iPad sold which doesn’t sound li…

Could it be something like this:

At software level iOS registers some calibration data (after some factory calibration) tied to that specific serial number (as calibration makes sense only for that specific instance of the panel anyway) so when serial number changes iOS can't find calibration data on device and continues uncalibrated instead of trying to use calibrations for another-serial screen (from the OS perspective).

It makes sense, if there actually is some sort of calibration going on in the first place of course.

Re: Apple Pencils don’t draw straight on replaced iPad screens

#12

Post by dv_dt »

sbalamurugan wrote: post #8
spdustin wrote: post #4

Seems to me like it might be a calibration issue, and third parties aren’t able to perform the calibration.

Apparently it is not. The reddit thread has an ex Apple employee who runs repair shops in Germany. He says if you just change the serial number of a iPad screen(using specialised hardware) in existing iPad this issue will appear. This seems to indicate that it’s intentionally done by Apple. Other option is that Apple bakes in calibration details of all possible serial numbers in every iPad sold which doesn’t sound li…

Could be calibration is looked up via serial number by the iPad and the third party ones don’t have any cal on file.

Re: Apple Pencils don’t draw straight on replaced iPad screens

#13

Post by alden5 »

A while ago there was an issue that when replacing a camera on an iphone 12 it would cause the camera to become unresponsive. The problem was later solved with a software update without much fanfare; Backing up the fact that it was a glitch, the problem never occurred on the 12 pro. but yea i definitely hate the serialization, especially considering it looks like their hardware design is becoming more repairable with the 14's back glass becoming removable, it makes their software lockdowns make even less sense.

Re: Apple Pencils don’t draw straight on replaced iPad screens

#14

Post by kiririn »

voyagerfan5761 wrote: post #3

Avoidant as I am of Apple's ecosystem, I can only imagine the "security" justification for serializing a display panel. Covert exfiltration of sensitive information from password managers and such? At any rate, I continue to be unamused by how difficult it is for normal people to service their own Apple devices.

For displays I imagine the reason is more reputation and experience - normally just about every apple product has a factory calibrated display, but that promise can be broken (intentionally or not) on the used market. It’s nice to have a means of checking whether a display is legit other than eyeballing it

That being said, I can’t think of a reason for blocking correct pencil functionality. It doesn’t seem like something that would need individual calibration

Re: Apple Pencils don’t draw straight on replaced iPad screens

#15

Post by JumpCrisscross »

sbalamurugan wrote: post #8
spdustin wrote: post #4

Seems to me like it might be a calibration issue, and third parties aren’t able to perform the calibration.

Apparently it is not. The reddit thread has an ex Apple employee who runs repair shops in Germany. He says if you just change the serial number of a iPad screen(using specialised hardware) in existing iPad this issue will appear. This seems to indicate that it’s intentionally done by Apple. Other option is that Apple bakes in calibration details of all possible serial numbers in every iPad sold which doesn’t sound li…

Serial numbers encode production-specific parameters. We don’t yet know how to produce uniform displays batch to batch. Running Toyota engine code on a Subaru will produce glitches without requiring any conspiracy.

Re: Apple Pencils don’t draw straight on replaced iPad screens

#16

Post by bpye »

can16358p wrote: post #11
sbalamurugan wrote: post #8

Earlier quoted context omitted.

Apparently it is not. The reddit thread has an ex Apple employee who runs repair shops in Germany. He says if you just change the serial number of a iPad screen(using specialised hardware) in existing iPad this issue will appear. This seems to indicate that it’s intentionally done by Apple. Other option is that Apple bakes in calibration details of all possible serial numbers in every iPad sold which doesn’t sound li…

Could it be something like this: At software level iOS registers some calibration data (after some factory calibration) tied to that specific serial number (as calibration makes sense only for that specific instance of the panel anyway) so when serial number changes iOS can't find calibration data on device and continues uncalibrated instead of trying to use calibrations for another-serial screen (from the OS perspec…

Yeah I think this is most likely. Then when you change the serial you're using the calibration data for the wrong screen, but most of the time you're lucky and the two screens behave close enough that an average user doesn't notice.

Re: Apple Pencils don’t draw straight on replaced iPad screens

#17

Post by hsbauauvhabzb »

randomuser23423 wrote: post #9
voyagerfan5761 wrote: post #3

Avoidant as I am of Apple's ecosystem, I can only imagine the "security" justification for serializing a display panel. Covert exfiltration of sensitive information from password managers and such? At any rate, I continue to be unamused by how difficult it is for normal people to service their own Apple devices.

> Avoidant as I am of Apple's ecosystem, I can only imagine the "security" justification for serializing a display panel. Covert exfiltration of sensitive information from password managers and such? They're a more valuable target for theft the more parts that can be "cleanly" sold.

Are ipad thieving gangs really breaking down and on selling stolen components?

Re: Apple Pencils don’t draw straight on replaced iPad screens

#19

Post by TillE »

hsbauauvhabzb wrote: post #17
randomuser23423 wrote: post #9

Earlier quoted context omitted.

> Avoidant as I am of Apple's ecosystem, I can only imagine the "security" justification for serializing a display panel. Covert exfiltration of sensitive information from password managers and such? They're a more valuable target for theft the more parts that can be "cleanly" sold.

Are ipad thieving gangs really breaking down and on selling stolen components?

If you make Apple devices totally worthless to thieves, you discourage theft. Make them bricks which can't even be harvested for parts.

That's the goal apparently, and it makes sense.

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